The present invention relates in general to web or strip material handling mechanisms, and more particularly to an entry guide for feeding strip material into the nip or bite area between a pair of mill rollers.
Strip mill entry guides are known in the art, as evidenced by U.S. Pat. 2,402,546 and 3,740,989. The function of entry guides is to control and properly position strip material as it is fed between an opposed pair of mill rolls or rollers wherein the strip is worked. For example, several stands or sets of mill rollers are used together to sequentially reduce relatively thick slab steel into relatively thin strip steel that is widely used as sheet metal in automotive, appliance, and other applications. When the slab steel is rolled at high temperature, the process is known as "hot milling", while the process of rolling lower temperature slab steel is known as "cold milling". While the present invention is pertinent to "cold milling" and other strip handling processes, its primary advantages are found in "hot milling" applications.
The "hot milling" of slab steel through a series of stands of mill rollers is a complex process requiring that the sets of rollers operate at different speeds, roller pressures and the like due to the gradual thinning and lengthening of the high temperature steel strip being rolled. Each stand of mill rollers requires an entry guide mechanism to effectively transfer the strip material to it from an adjacent set of rollers. The entry guide mechanism must serve two primary functions, i namely feeding or threading the leading edge of the strip into the nip of the associated mill rollers, and then maintaining the strip of material in proper position as its length continues through the nip of the associated rollers. Ideally, the entry guide mechanism for each stand should be generally identical to permit interchangeability and facilitate maintenance. By being generally identical to each other, each entry guide mechanism must be able to accommodate strip material traveling at different speeds and having different thicknesses and thus masses. Also, the entry guide mechanism must be of a design and construction that is rugged and user accommodating so as to provide for reliable operation under adverse conditions common in a "hot milling" environment.